Tag: redis

  • Redis error currently not able to persist on disk

    Redis error currently not able to persist on disk

    When doing a FLUSHALl on redis server, i get following error message

    [root@server ~]# redis-cli FLUSHALL
    (error) MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.
    [root@server ~]#

    The error was because redis data directory was not properly configured.

    To fix, the error, edit redis config file

    vi /etc/redis/redis.conf

    Find

    dir ./

    Replace with

    dir /var/lib/redis

    Create a directory

    mkdir /var/lib/redis

    Make it owned by user redis

    chown redis:redis /var/lib/redis

    Restart redis server

    systemctl restart redis

    See Redis

  • How to flush Redis cache

    How to flush Redis cache

    To delete everything from redis cache, run the command

    redis-cli FLUSHDB

    This will delete all keys from the current DB.

    To delete cache from all DB, run

    redis-cli FLUSHALL

    If Redis is on another server or needs password, you can use the following command

    redis-cli -h IP_HERE -p PORT_HERE -a PASSWORD_HERE FLUSHDB

    See Redis

  • How to find Redis data directory

    How to find Redis data directory

    To find the data directory in redis, run the command

    redis-cli config get dir

    redis data directory

    Redis data directory is specified in the configuration file

    /etc/redis/redis.conf

    The entry is

    dir /var/lib/redis

    redis data directory should be owned by user redis

    chown redis:redis /var/lib/redis

    Example

    [root@server redis]# cd /var/lib/redis/
[root@server redis]# ls -la
total 12
drwxrwx---   2 redis redis 4096 Dec  2 06:44 .
drwxr-xr-x. 37 root  root  4096 Nov 20 17:30 ..
-rw-r--r--   1 redis redis   92 Dec  2 06:44 dump.rdb
[root@server redis]#

    See Redis

  • Install latest Redis on Ubuntu/Debian Server

    Install latest Redis on Ubuntu/Debian Server

    To install the latest version of Redis on Ubuntu/Debian server, run

    curl https://packages.redis.io/gpg | sudo apt-key add -
echo "deb https://packages.redis.io/deb $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/redis.list
sudo apt-get update
sudo apt-get install redis

    Enable redis server to start on boot

    systemctl enable redis-server

    Start redis server

    systemctl start redis-server

    See Redis

  • redis commander

    redis-commander is a GUI for redis. To install, run

    npm install -g redis-commander
redis-commander

    redis commander

  • Install Redis from Source

    Install Redis from Source

    To install Redis from the source, run

    cd /usr/local/src
wget http://download.redis.io/redis-stable.tar.gz
tar xvzf redis-stable.tar.gz
cd redis-stable
make
make install

    Copy config file

    mkdir /etc/redis/
cp /usr/local/src/redis-stable/redis.conf  /etc/redis/

    Create redis user

    groupadd -r redis
useradd -r -g redis -s /sbin/nologin -d /var/lib/redis -c "redis Daemons" redis

    Create directory

    mkdir /var/lib/redis
chown redis:redis /var/lib/redis
chmod 770 /var/lib/redis

    Set data directory

    vi /etc/redis/redis.conf

    Find

    dir ./

    Replace with

    dir /var/lib/redis

    Create service file

    vi /usr/lib/systemd/system/redis.service

    Add the following content to the file

    [Unit]
Description=Redis persistent key-value database
After=syslog.target

[Service]
ExecStart=/usr/local/bin/redis-server /etc/redis/redis.conf
RestartSec=5s
Restart=on-success
User=redis
Group=redis

[Install]
WantedBy=multi-user.target

    Enable and start Redis

    systemctl enable redis
systemctl start redis

    To find Redis version, run

    redis-server --version

    To monitor Redis, you can use redis-cli

    Back to redis

  • Install Redis on Plesk Debian Server

    Install Redis on Plesk Debian Server

    To install Redis on Plesk Debian/Ubuntu server, run

    apt install -y redis-server redis-tools

    Enable and restart redis-server

    systemctl enable redis-server
systemctl restart redis-server

    Now install PHP Modules

    apt install -y plesk-php70-redis plesk-php71-redis plesk-php72-redis plesk-php73-redis plesk-php74-redis

    After installing, you will see redis listed in phpinfo() page.

    Redis PHP Debian

  • Monitor redis with redis-cli

    On Ununtu/Debian, install it with

    apt -y install redis-tools

    To get stats, run

    redis-cli --stat

    If your redis on differnt sevrer or use non standard port, then use

    redis-cli -h HOSTNAME -p PORT --stat

    Example

    root@ip-10-0-0-31:~# redis-cli -h news24redis.cylrbg.0001.use1.cache.amazonaws.com --stat
------- data ------ --------------------- load -------------------- - child -
keys       mem      clients blocked requests            connections          
9287       20.58M   27      0       179271 (+0)         1208        
9287       20.62M   27      0       179277 (+6)         1208        
9288       20.67M   28      0       179377 (+100)       1209        
9288       20.64M   28      0       179494 (+117)       1209        
9292       20.71M   28      0       179823 (+329)       1210        
9292       20.68M   28      0       179969 (+146)       1211        
9298       20.74M   29      0       180033 (+64)        1212        
9311       20.67M   28      0       180162 (+129)       1214        
9314       20.69M   29      0       180198 (+36)        1215        
9318       20.80M   30      0       180275 (+77)        1216        
9318       20.68M   30      0       180280 (+5)         1216        
9318       20.82M   31      0       180307 (+27)        1218        
9319       20.74M   31      0       180321 (+14)        1218        
9322       20.70M   29      0       180350 (+29)        1219        
9324       20.80M   30      0       180377 (+27)        1220        
9366       20.90M   30      0       180724 (+347)       1221        
9368       20.77M   29      0       181086 (+362)       1221        
9368       20.73M   27      0       181133 (+47)        1221        
9372       20.73M   27      0       181487 (+354)       1222        
9380       20.73M   27      0       181592 (+105)       1223        
------- data ------ --------------------- load -------------------- - child -
keys       mem      clients blocked requests            connections          
9384       20.76M   28      0       181639 (+47)        1224        
9391       20.77M   28      0       181718 (+79)        1224        
9391       20.79M   27      0       181731 (+13)        1224        
9391       20.67M   25      0       181771 (+40)        1224        
9391       20.67M   25      0       181780 (+9)         1224        
9391       20.67M   25      0       181849 (+69)        1224        
^C
root@ip-10-0-0-31:~#

    INFO

    redis-cli INFO

    If you want to see info about clients, run

    redis-cli INFO clients

    Monitor

    To see what redis is doing, run

    redis-cli monitor

    If your redis is running on remote server, then use

    redis-cli -h REMOTE_SERVER_IP monitor

  • Install Redis PHP module in Ubuntu 16.04

    To install redis php module in Ubuntu 16.04, run

    apt -y install php-redis

    If you are using Apache, restart Apache.

    systemctl restart apache2

    If php-fpm restart

    systemctl restart php7.0-fpm

    You will see following in your phpinfo()

    php redis

  • redis

    Install Redis

    Install latest Redis on Ubuntu/Debian Server
    Install Redis on Plesk Debian Server
    Install Redis from Source

    How Tos

    Installing Redis PHP module CentOS 7
    Connect to redis from PHP
    Monitor redis with redis-cli
    redis commander – Web GUI for Redis
    How to find Redis data directory
    How to flush Redis cache
    Redis error currently not able to persist on disk

    Checking if Redis works

    # telnet 127.0.0.1 6379
set testkey 10
get testkey

    Example

    root@ip-10-0-0-31:~# telnet news24redis.cylrbg.0001.use1.cache.amazonaws.com 6379
Trying 10.0.0.223...
Connected to news24redis.cylrbg.0001.use1.cache.amazonaws.com.
Escape character is '^]'.
set testkey 10
+OK
get testkey
$2
10
quit
+OK
Connection closed by foreign host.
root@ip-10-0-0-31:~#

    Count Number of Keys

    To count number of keys, use

    DBSIZE

    Example

    root@ip-10-0-0-31:~# telnet news24redis.cylrbg.0001.use1.cache.amazonaws.com 6379
Trying 10.0.0.223...
Connected to news24redis.cylrbg.0001.use1.cache.amazonaws.com.
Escape character is '^]'.
DBSIZE
:4114

    Here DBSIZE returned 4114, that means you have that much key/value stored in redis.

    Flush ALl

    To flush all keys, use

    redis-cli flushall

  • Install Redis PHP Module from source

    To install Redis PHP module from source, run

    cd /usr/local/src
git clone https://github.com/phpredis/phpredis.git
cd /usr/local/src/phpredis
/usr/serverok/php-7.1.12/bin/phpize
./configure --with-php-config=/usr/serverok/php-7.1.12/bin/php-config
make && make install

    Once installed, edit your php.ini file, add following below extension_dir line

    extension=redis.so

    Verify redis is installed with php -m

    [root@vps154294 ~]# /usr/serverok/php-7.1.12/bin/php -m | grep redis
redis
[root@vps154294 ~]#

    Now restart web server 

    service httpd restart

    phpinfo() will show following

    phpinfo redis

  • Installing Redis PHP module CentOS 7

    Lets search for available redis packages

    [root@vps154294 smartfst]# yum search redis
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * epel: mirror.us.leaseweb.net
 * remi-safe: repo1.ash.innoscale.net
============================================================================================ N/S matched: redis ============================================================================================
collectd-redis.x86_64 : Redis plugin for collectd
collectd-write_redis.x86_64 : Redis output plugin for collectd
hiredis.x86_64 : Minimalistic C client library for Redis
hiredis-devel.x86_64 : Development files for hiredis
hiredis-last.x86_64 : Minimalistic C client library for Redis
opensips-redis.x86_64 : Redis connector
pcp-pmda-redis.x86_64 : Performance Co-Pilot (PCP) metrics for Redis
perl-Apache-Session-Redis.noarch : Redis driver for Apache::Session::NoSQL
perl-Redis.noarch : Perl binding for Redis database
php-nrk-Predis.noarch : PHP client library for Redis
php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php-phpiredis.x86_64 : Client extension for Redis
php54-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php54-php-phpiredis.x86_64 : Client extension for Redis
php55-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php55-php-phpiredis.x86_64 : Client extension for Redis
php56-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php56-php-phpiredis.x86_64 : Client extension for Redis
php70-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php70-php-phpiredis.x86_64 : Client extension for Redis
php71-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php71-php-phpiredis.x86_64 : Client extension for Redis
php72-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php72-php-phpiredis.x86_64 : Client extension for Redis
python-redis.noarch : Python 2 interface to the Redis key-value store
python-trollius-redis.noarch : Redis client for the Python event loop PEP3156 for Trollius.
python2-django-redis.noarch : Full featured redis cache backend for Django
redis-trib.noarch : Cluster management script for Redis
rubygem-redis.noarch : A Ruby client library for Redis
rubygem-redis-doc.noarch : Documentation for rubygem-redis
syslog-ng-redis.x86_64 : redis support for syslog-ng
uwsgi-logger-redis.x86_64 : uWSGI - redislog logger plugin
uwsgi-router-redis.x86_64 : uWSGI - Plugin for Redis router support
redis.x86_64 : A persistent key-value database

  Name and summary matches only, use "search all" for everything.
[root@vps154294 smartfst]#

    In this server, we have PHP 7.0 installed. So we need to install packages for PHP 7.0

    Here are the two packages for PHP 7.0

    php70-php-pecl-redis.x86_64 : Extension for communicating with the Redis key-value store
php70-php-phpiredis.x86_64 : Client extension for Redis

    Install it with yum

    yum install -y php70-php-pecl-redis.x86_64 php70-php-phpiredis.x86_64

    Now you need to restart web server, generally restarting apache will do. In this cause PHP is running as php-fpm under nginx, so we need to restart php-fpm with

    systemctl restart php-fpm